MBC’s “Idol Star Athletics Championships,” a variety show featuring droves of K-pop stars competing across different sports events, has once again come under fire, following a series of injuries sustained by participants.

Controversies over the show’s safety arose as Ungjae of K-pop boy band Impact was reportedly rushed to a hospital for shoulder pain after a shoot that took place at Goyang Gymnasium in Gyeonggi Province, Monday.

It was revealed the singer, who had already been receiving treatment for a previous shoulder injury, suffered pain after an acrobatic performance as one of the main sports events of the program. On the same day, Sana of Twice was also reported to have been taken to a hospital for enteritis while shooting the same episode.

Scenes from “Idol Star Athletic Championships” (MBC)

The two K-pop stars’ agencies later said the stars were recovering. However, furious fans have been flooding social media with complaints about the accident-ridden program’s safety issues, even requesting the channel to shut down the show.

Spurred by the idea of watching fan-favorite K-pop stars in fierce sports competitions, including rhythmic gymnastics, aerobics and archery, “ISAC” has cemented itself as one of the most popular holiday shows since its first episode in 2010. The star-studded show, which annually airs around Lunar New Year’s Day in the winter and Chuseok in the fall, has also been on the to-do list of many K-pop stars, especially rookies, as it is considered a shortcut to gaining broad public recognition.

Despite its unwavering popularity, “ISAC” has found itself embroiled in safety problems since 2013, when Bora of Sistar and Daniel of DMTN sustained leg injuries. In 2014, Seolhyun of AOA was forced to withdraw from group activities after sustaining a serious leg injury on the show, while Woohyun of Infinite ruptured his shoulder ligament. In 2015, Moonbyul of Mamamoo and L.Joe, formerly of Teen Top, injured a leg and finger, respectively, and Xiumin of EXO hurt his leg in 2016.

Scenes from “Idol Star Athletic Championships” (MBC)

Amid mounting criticism, production staff recently announced a plan to implement extra safety measures, such as adding to the medical team at the set, and focusing on artists’ safety starting this year.

Fans, however, have still pointed to the program as responsible for the injuries. Following Ungjae’s incident, online commenters took turns sharing photos on social media that showed the set’s racing lane covered with adhesive sheets. Comments read, “The lane is made of adhesive sheets. Does it makes sense? It’s a miracle they do not to fall down while running on it” and “Did you (the staff) use those sheets to save money? Please take care of the artists.”

Some claimed the K-pop stars, who are not well versed in the sports, could be more susceptible to injuries than others as they have to cram the competition rules in a short period before the shoot and jump right into the games without adequate preparation.

Scenes from “Idol Star Athletic Championships” (MBC)

This year’s “ISAC,” hosted by TV personality Jeon Hyun-moo, Leeteuk of Super Junior and Bomi of Apink, features 23 K-pop acts, including EXO, Wanna One, Twice, Red Velvet, Monsta X, GFriend, Mamamoo and Lovelyz. The show will air during the Lunar New Year’s holiday period in February.